Print hammer modules for high speed printers



Aug. 17, 1965 c. .1. ANTONUCCI 3,200,739

PRINT HAMMER MODULES FOR HIGH SPEED PRINTERS Filed March 18, 1965 2 SheetsSheet 1 INVENTOR. f m/mid4A m/va x/ ATTORNE y' 1965 c. J. ANTONUCCI 3,200,739

PRINT HAMMER MODULES FOR HIGH SPEED PRINTERS Filed March 18, 1963 2 Sheets-Sheet 2 United States Patent 3,200,739 PRINT HAMMER MODULES FOR HIGH SPEED PRINTERS Carmine J. Antonucci, Uniondale, N.Y., assignor to Potter Instrument Company, Inc., Plainview, N.Y., a corporation of New York Filed Mar. 18, 1963, Ser. No. 265,621 Claims. (Cl. 101-93) This invention relates to hammer modules for high speed printers.

In recent years, high speed printers have been of increased interest to the art in order to print out information processed by data processing equipment. High speed printers utilizing hammer modules in which each individual hammer is supported by a suitable bearing for pivoting about an axis are known to the art. A printing head is provided on one end of each hammer in the hammer module, and an armature is provided on the other end. An electromagnet is positioned adjacent the armature to pivot the hammer about the axis driving the printing head into impact engagement with a recording medium. .Such engagement transfers indicia to the recording medium from a font positioned adjacent the recording medium.

Pluralities of such hammers are usually assembled into hammer modules, usually made in groups of four hammers.

With increases in speeds of data processing and printing, one problem that has existed with such modules has bearing wear has become increasingly serious.

Further, it is desirable in such modules that the spacing between each armature and the core of each electromagnet be adjustable precisely.

It is a primary object of the present invention to provide a hammer module in which the bearing surface can be increased without overall increase in the size of the hammer module.

It is a further object of this invention to provide an improved hammer module of compact size in which the bearing surface area is increased and in which the positioning of the electromagnets can be controlled adjustably.

In accordance with these objects, there is provided in a preferred embodiment of the present invention, a hammer module having a frame within which is positioned a first and second shaft. The first and second shafts are mounted in a parallel, spaced-apart orientation. A first printing hammer having a substantially straight hammer arm, at one end of which is supported a printing head and at the other end of which is supported an armature, is mounted pivotally on the first shaft. A first electromagnet is mounted in the frame adjacent the armature, and means are provided to adjust the clearance between the electromagnet and the armature.

A second printing hammer includes a hammer arm which is mounted pivotally on the second shaft and, like the first hammer, is provided with a printing head on one end and an armature on the other end. The arm of the second hammer is formed so that a line from the printing head through the pivotal axis defines an obtuse angle with a line from the armature through the pivotal axis. Similarly, a second electromagnet is adjustably positioned adjacent said armature to effect a pivoting of said second printing hammer.

Since the two shafts are spaced apart, bearing assemblies upon which the respective, adjacent hammers are mounted can be doubled in length. Thus, in this manner, close spacing of adjacent hammers may be effected without requiring concomitant reduction in bearing length.

3,200,739 Patented Aug. 17, 1965 "ice This invention may be understood more readily by reference to the following detailed description of the specification which maybe understood best by reference to the accompanying drawings, in which:

FIG. 1 is an elevation view of a hammer module constructed in accordance with the present invention;

FIG. 2 is a cross-section view taken along lines 22 of FIG. 1;

FIG. 3 is a cross-section view of FIG. 1; and

FIG. 4 is a cross-section view of FIG. 1.

In the drawings, there is shown a hammer module having a frame 10 which is provided with a first and second side plates 12 and 14, respectively and which is provided with a third mounting plate 16 positioned therebetween to support a first bearing shaft 18 and a second bearing sthaft 20 therewithin in a spaced-apart, parallel relations 1p.

Each shaft is provided with a flat surface 24 to receive thefpoint of a set screw 27 for positive location of the sha t.

Printing hammers are mounted pivotally upon both of the shafts 13 and 20. In the embodiment illustrated, four hammers 26, 28, 30 and 32 are located within the module, as defined by the end plates 12 and 14.

Each hammer is provided with a printing head 32' at one end thereof and, conventionally, formed integrally therewith. An armature 34 is supported at the other end of each hammer.

A separate electromagnet is of the armatures. As seen in FIG. 1, the hammer arm 26 supports, at one end, an armature 34, and an electromagnet 36 is positioned with the poles 36a and 36b of taken along lines 3-3 taken along lines 4-4 positioned adjacent each the core 6t) adjacent the armature 34. When energized momentarily, the hammer arm 26 will pivot about the pivotal axis 33 against the bias of a spring 40 mounted to the frame by means of .a fixture 42 to strike a type carrier drum 44. It is customary to interpose a recording medium 43 intermediate the head 32' and the drum 44.

A stop 46 is utilized to define the rest position of the hammer head 32' and is adjustable to permit alteration of the distance which the head 32' must travel.

The hammer arm 26 is supported by a bearing 48, FIG. 3, as, for example, by press fitting the hammer arm onto an outer sleeve 50a. The bearing 48 extends the entire distance between the end or side plate 12 and the middle plate 16 and is positioned accurately by a shim 52.

Similarly, the hammer arm 28 is mounted on a bearing 49 by means of a sleeve 50 for pivoting about the shaft 20.

The hammer arm 26 is substantially straight extending from the printing head 32' to the armature 34. However, in order to permit the hammers 26 and 23 to be mounted both within the same space, defined between the plates 12 and 16, the hammer arm 28 is formed so that the angle identified by the numeral 54 in FIG. 1 is an obtuse angle.

An electromagnet 56, for pivoting the hammer arm 28, is attached to the frame so that the core 58 thereof will be disposed with its poles 58a and 58b at right angles to the direction of the poles 36a and 36b of the electromagnet 36. In this manner, the length of the bearings 48 and 49 may be coextensive with the dimension between the plates 12 and 16.

This massive bearing construction will permit reliable operation at high printing speeds over an extended life time. At the same time, however, the hammer assemblies will be confined within the space defined by the plates 12 and 16.

The structure surrounding the hammers 30 and 32 is the same as that just described for the hammers 26 and 28.

Since the clearance between the armature and the electromagnets must be defined with extreme precision, it is advantageous to provide for adjustably moving the electromagnets by means of set screws 62 and 64, FIG. 1. When the desired spacing between the armature and the core has been attained, the electromagnet may be fixedly secured by a lock nut 66 on a through bolt 68, seen also in F IG. 4.

To further reduce the module size and to increase the operating reliability thereof, it is advantageous to employ a core material sold under the tradename Hyperco by Westinghouse Electric Company. This core material permits the development of magnetic flux densities in the order of 24,000 gauss, as contrasted with about 16,000 gauss for ordinary core materials.

This invention may be variously modified and embodied within the scope of the subjoined claims.

What is claimed is:

1. A -hammer module comprising,

'a frame consisting of first and second side plates and a third plate intermediate said first and second plates,

a first and second shaft positioned in parallel separated locations and extending through said'third plate and into said first and second side plates,

a first bearingmounted on said first shaft and extending between said first and third plates,

at second bearing mounted on said first shaft and extending between said second and third plates,

at third bearing mounted on said second shaft and extending between said first and third plates,

a fourth bearing mounted on said second shaft and extending between said second and third plates,

a first printing hammer mounted on said first bearing on the end adjacent said first plate,

a second printing hammer mounted on said second bearing on the end adjacent said third plate,

a third printing hammer mounted on said third bearing at the end adjacent said third plate,

a fourth printing hammer mounted on said fourth bearing at the end adjacent said second plate,

each of said printing hammers having a printing head at one end thereof,

said printing heads being aligned,

each of said printing hammers having a soft magnetic armature at the other end thereof,

said first and second printing hammers being substantially straight,

said third and fourth printing hammers being shaped about the second shaft so that the angle defined by said printing head, second shaft, and armature is an obtuse angle, and electromagnetic coils positioned adjacent each armature to actuate each printing hammer selectively.

2. A hammer module comprising,

a frame,

a first shaft and second shaft mounted within said frame at parallel positions adjacent each other,

a first printing hammer mounted pivotally on said first shaft and having a head portion extending from said frame,

a second printing hammer mounted pivotally on said second shaft and having a head portion adjacent said head portion of the first printing hammer,

each of said printing hammers having elongated body members extending substantially coextensively from said shafts to the head portions and spaced apart a predetermined distance from each other,

bearing means on each of said shafts and having an axial length greater than one-half of said predetermined distance for supporting each respective printing hammer on its respective shaft,

said first printing hammer being substantially straight and having a printing head on one end thereof and an armature at the other,

a first electromagnet positioned adjacent said first armature to attract said armature thereto when energized,

said second printing hammer being formed to define an obtuse angle between the printing head, said second shaft, and an armature positioned at the other end 'in said frame and extending into contact with said electromagnets, and means to secure said electromagnets in position.

5. A hammer module in accordance with claim 2 including a plurality of printing hammers having heads aligned similar to the heads of said first and second printing hammers, and having respective bearing means similar to the bearing means for said first and second printing hammers.

References Cited by the Examiner UNITED STATES PATENTS 1,547,150 7/25 Von 101-90 X 2,427,418 9/47 Rast 101-90 2,659,652 11/53 Thompson 346-50 2,787,210 4/57 Shepard 101-93 2,813,480 11/57 Fowler 101-93. 2,940,385 6/60 House 10193 3,012,499 12/61 A-mada 101-93 WILLIAM B. PENN, Primary Examiner. 

1. A HAMMER MODULE COMPRISING, A FRAME CONSISTING OF FIRST AND SECOND SIDE PLATES AND A THIRD PLATE INTERMEDIATE SAID FIRST AND SECOND PLATES, A FIRST AND SECOND SHAFT POSITIONED IN PARALLEL SEPARATED LOCATIONS AND EXTENDING THROUGH SAID THIRD PLATE AND INTO SAID FIRST AND SECOND SIDE PLATES, A FIRST BEARING MOUNTED ON SAID FIRST SHAFT AND EXTENDING BETWEEN SAID FIRST AND THIRD PLATES, A SECOND BEARING MOUNTED ON SAID FIRST SHAFT AND EXTENDING BETWEEN SAID SECOND AND THIRD PLATES, A THIRD BEARING MOUNTED ON SAID SECOND SHAFT AND EXTENDING BETWEEN SAID FIRST AND THIRD PLATES, A FOURTH BEARING MOUNTED ON SAID SECOND SHAFT AND EXTENDING BETWEEN SAID SECOND AND THIRD PLATES, A FIRST PRINTING HAMMER MOUNTED ON SAID FIRST BEARING ON THE END ADJACENT SAID FIRST PLATE, A SECOND PRINTING HAMMER MOUNTED ON SAID SECOND BEARING ON THE END ADJACENT SAID THIRD PLATE, A THIRD PRINTING HAMMER MOUNTED ON SAID THIRD BEARING AT THE END ADJACENT SAID THIRD PLATE, A FOURTH PRINTING HAMMER MOUNTED ON SAID FOURTH BEARING AT THE END ADJACENT SAID SECOND PLATE, EACH OF SAID PRINTING HAMMERS HAVING A PRINTING HEAD AT ONE END THEREOF, SAID PRINTING HEADS BEING ALIGNED, EACH OF SAID PRINTING HAMMERS HAVING A SOFT MAGNETIC ARMATURE AT THE OTHER END THEREOF, SAID FIRST AND SECOND PRINTING HAMMERS BEING SUBSTANTIALLY STRAIGHT, SAID THIRD AND FOURTH PRINTING HAMMERS BEING SHAPED ABOUT THE SECOND SHAFT SO THAT THE ANGLE DEFINED BY SAID PRINTING HEAD, SECOND SHAFT, AND ARMATURE IS AN OBTUSE ANGLE, AND ELECTROMAGNETIC COILS POSITIONED ADJACENT EACH ARMATURE TO ACTUATE EACH PRINTING HAMMER SELECTIVELY. 